If you look at the text of the legislation you'll see they've prevented the Secretary of Transportation from granting access to Mexican trucks outside of border areas except for the pilot program. That means Bush's plan to automatically grant unlimited access after one year is history.
Also the 1,000 truck number is the total number, not a per company number.
They've also mandated the the Secretary of Transportation study the impact of such things as effects on public safety and compliance of the Mexican companies with our HOS laws and truck safety laws.
There's 4 versions of the bill:
http://thomas.loc.gov/cgi-bin/query/z?c110:H.R.1773: